This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-228195, filed Jul. 27, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an X-ray diagnostic apparatus having a tilting bed.
2. Description of the Related Art
X-ray diagnostic apparatuses, many of X-ray diagnostic apparatuses designed for the digestive system such as the stomach, duodenum, and small intestine as targets to be imaged, in particular, are equipped with a bed which can freely tilt in the range of a vertical position (+30xc2x0) to the head down vertical position (xe2x88x9230xc2x0). This makes it possible to hold an object to be examined in a posture in which an optimal effect of a contrast medium can be obtained.
A cassette or X-ray detector is mounted below the top of the bed. An X-ray tube is supported by a support at a high position where it faces the X-ray detector. The support is fixed to the frame of the bed. With this structure, the support is tilted together with the bed.
Such a digestive system X-ray diagnostic apparatus has the following problem to be solved.
As is known, an X-ray tube constitutes an X-ray diagnostic apparatus, together with a stop unit and the like. The X-ray diagnostic apparatus is very heavy. A support which supports the heavy X-ray diagnostic apparatus, a bed frame which supports the X-ray diagnostic apparatus together with the support, and a base which supports the bed frame are required to have high rigidity. In addition, very large driving force is required to quickly and smoothly tilt the heavy X-ray diagnostic apparatus, heavy support, and heavy bed frame.
Such a heavy, large X-ray diagnostic apparatus narrows the space where a doctor makes an approach to a patient during IVR (interventional radiology) in which treatment is done under fluoroscopy.
The invention disclosed in Jpn. Pat. Appln. KOKAI Publication No. 11-206744 has a structure in which a C-arm which supports an X-ray tube unit together with an image intensifier and TV camera is cantilevered by a stand different from a bed, and is especially characterized by a design in which the tilt axis of the arm stand is matched with the tilt axis of the bed. This design allows the shared use of a drive source for bed tilting and C-arm tilting.
This design, however, leads to an increase in the size of the arm stand, and requires the arm stand to be located close to the bed. This limits the approach space to a narrow space. In addition, according to the above design, the arm stand and the bed are always set in pair. For this reason, an object to be examined on a member other than the top, e.g., a stretcher, cannot be imaged.
It is an object of the present invention to increase the approach space and the degree of freedom in imaging in an X-ray diagnostic apparatus having a tilting bed.
According to the first aspect of the present invention, there is provided an X-ray diagnostic apparatus comprising an arm supporting an X-ray tube and an X-ray detector, a tilting bed, a joining mechanism detachably joining the arm to the bed, and an arm support mechanism freely supporting the arm such the arm follows a tilting of the bed
According to the second aspect of the present invention, there is provided an X-ray diagnostic apparatus comprising a tilting bed, an arm supporting an X-ray tube and an X-ray detector and being structurally isolated from the bed, and an arm support mechanism being structurally isolated from the bed and freely supporting the arm.
According to the third aspect of the present invention, there is provided an X-ray diagnostic apparatus comprising a tilting bed, an arm mounting an X-ray tube and an X-ray detector, an arm support mechanism configured to freely support the arm, a rotation driving unit configured to drive rotation of the arm, a horizontal displacement driving unit configured to drive horizontal displacement of the arm, a rise/fall driving unit configured to drive rising/falling of the arm, and a control unit configured to control the rotation driving unit, the horizontal displacement driving unit, and the rise/fall driving unit to make the arm rotate, translate, and rise/fall in accordance with tilting of the bed.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.